The measurement of amylase in drain fluid for the detection of pancreatic fistula after gastric cancer surgery: an interim analysis

BACKGROUND Pancreatic fistula is still one of the most serious and potential complications after D2-D3 distal and total gastrectomy (4% to 6%). Despite their importance, pancreatic fistulas still have not been uniformly defined. Amylase concentration of the drainage fluid after surgery for gastric cancer can be considered as a predictive factor of the presence of pancreatic fistula. METHODS From January 2009 to April 2013, 53 patients underwent surgery for gastric cancer. Amylase concentration in the drainage fluid was measured on the first postoperative day and if it was ≥1,000 UI, it was measured again on the third postoperative day. Pancreatic fistula occurred in four cases (7.5%). Pancreatic fistulas were classified using the International Study Group on Pancreatic Fistula (ISGPF) criteria into different grades of severity. Two fistulas were Grade A, one was Grade B, and one was Grade C. RESULTS Management of drainage tubes is still crucial after gastrectomy, not only for the likelihood of anastomotic leaks but also the eventual diagnosis and management of pancreatic fistula. High amylase drainage content and then the presence of the pancreatic fistula may be due to several causes: the operation itself when it includes splenectomy or pancreatic tail-splenectomy, the extended lymphadenectomy but even the 'gently and softly' pancreatic manipulation, according literature, may be a risk factor. CONCLUSIONS The authors assessed amylase concentration in the drainage fluid collected from the left subphrenic cavity on POD1 and POD3 in 53 patients who had undergone curative gastrectomy for cancer and concluded that amylase drainage content >3 times the serum amylase was a useful predictive risk factor for pancreatic fistula. Our work is an interim analysis and the aim of this study is to increase the accrual of the number of patients to have a significant number. For this reason, a protocol for a multicenter trial will be designed to verify whether the systematic measurement of amylase in drain fluid is better than abdominal ultrasound for the detection of pancreatic fistula after gastric cancer surgery.